A multitude of devices are known in the prior art for moving vehicle seats fore and aft in relation to a frame of a vehicle. Most of the assemblies found in the prior art relate to seat tracks upon which the seat bracket and the seat attached thereto are releasably moveable. However these assemblies are heavy in construction and add to the weight of the vehicle unnecessarily.
Further there exists a number of devices for the movement of a seat which generally do not rely on rails to provide the fore and aft movement of the seat but provide pivotable members attached to the seat bracket to move the seat in relation to the frame. Examples of such assemblies are described below.
U.S. Pat. No. 4,807,932 issued on Feb. 28, 1989 to Kia Motors describes a device for moving an automobile seat back and forth including legs pivotable to the frame which move the seat along an arcuate path.
U.S. Pat. No. 4,121,802 issued on Oct. 24, 1978 to Keiper KG describes a device as illustrated in relation to FIG. 2 including a linkage operative for vertical movement of the carrier in relation to a base.
PCT Application WO 91/04881 published on Apr. 18, 1991 describes the parallel motion between a seat and a support frame which includes a system of links.
West German Patent Application 4,010,451 published on Oct. 2, 1991 and Assigned to Audi describes the longitudinal motion of a seat by means of a four bar linkage system. The motion of the seat is clearly arcuate as seen in the figures.
Finally, West German Patent Application 2,855,293 published on Jul. 3, 1980 to Fichtel & Sachs AG describes a multi-link adjustment member for a seat which purports to provide generally linear motion of the seat.
Nowhere within the prior art is there found a preferably compact adjustment mechanism for a seat which includes a linkage system including a compensating link to compensate for the arcuate motion of the primary links of the mechanism rendering the final longitudinal motion of the seat as substantially linear within the range of motion of the seat.
It is therefore an object of this invention to provide a seat adjustment mechanism which includes a linkage system moveable within the limits of motion of the seat to a predetermined number of positions wherein the linkage system includes a compensating link to compensate for the arcuate motion of the primary links of the mechanism, during the fore and aft movement of the seat, rendering the final longitudinal motion of the seat as substantially linear within the range of motion of the seat. It is particularly advantageous to provide a compact design to minimize the space required for the installation of the assembly.
It is another object of this invention to provide a mechanism which operates silently and requires little lubrication.
It is a further object of the invention to provide a seat adjuster which is lightweight compact and economical to manufacture.
Further and other objects of this invention will become apparent to a man skilled in the art when considering the following summary of the invention and the more detailed description of the preferred embodiment illustrated herein.